Take clean stainless steel pot, add passion fruit juice and a lot of crystal sugar (about 1.5 -2 times the volume of juice) and bring to a boil over medium heat, then turn to low heat. Be sure to stir frequently, and turn off the fire when the rock sugar is almost completely melted or can no longer be dissolved (at this time, the liquid should be slightly thicker, and a drop can be filtered slightly. If the rock sugar is still very thin after melting, you can continue to add rock sugar)
It's best to take a hot bottle, open the bottle mouth and cool it thoroughly, then seal it. Sweet and sour. You can eat it naked or with dessert or juice.